$(this).is(":hidden"); //If the element is hidden, it returns true
is is very easy to use. It can use the jQuery selector as a parameter, especially with the selector in jQuery. The filter characters starting with colon are used together to achieve various judgments. Such as: ":checked,:hidden" and so on. Give an example:
<head>
<script src="jquery-1.7.1.js" type="text/javascript"></script>
<script type="text/javascript">
$(function () {
$(":button").click(function () {
if ($(this).is(":button")) {
alert("我是一个按钮!");
}
if ($("#check1").is(":checked")) {
alert("我是被选中的");
}
if ($(".p1").is(":visible")) {
alert("p1是可见的");
}
})
})
</script>
</head>
<body>
<div id="div1">
<p class="p1">我是一个p</p>
<input id="check1" type="checkbox" value="" />复选框
<input type="button" value="确认" />
</div>
</body>
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
